Tobi Tobin: No, no, it's not like that! I just catch glimpses of myself sometimes. The mirrors aren't about seeing me; they're about creating modernity in my 100-year-old farmhouse, injecting a little Mondrian.

You mean Mondrian the painter?

Yes, I call it using a Mondrian map. I measure the walls, and then I draw up blueprints for the mirrors, mimicking patterns in Mondrian's paintings of squares and rectangles. Copy a genius and you can't go wrong! I did a little Mondrian on the wall over my bed, and again in the living room, where I thought a grid would cut the old-fashioned feel of the curved moldings. In the entry, I hung mirrors to look like the portraits you see going up the grand staircases in English country houses. But they're not paintings, they're mirrors, so it's modern!

Darkness is important! Black is a must; it's the grounding element. The living room fireplace, the trim on the doors, they're all in this shiny, high-gloss black that reminds me of the glossy front doors you see in London — traditional, elegant, but somehow modern, too. Upstairs, I used black window valances in every single room, and outside, there's the black fireplace. I painted that fireplace white at first, but it grabbed way too much attention. Now it almost disappears.

How would you describe your style?

At its core, my style is all about neutrals. My clients are often artists, and I believe you have to live in a neutral palette in order to be creative. It feeds the soul. I write every night — I even published a novel — so I know that if you live in a loud environment, the volume is on too high to hear your own thoughts. Artists don't need somebody else's color; they need a neutral place to create color of their own.

But what about this beautiful biscuit shade you've used in every room — tables, chair legs, even the woven rugs?

That's actually a noncolor I call 'fruitwood' or 'pearwood.' It's a natural wood tone that always warms up a black-and-white palette. And it feels sort of modern and midcentury, with a touch of old Palm Beach. That color is the 'through-line,' as we say here in L.A. In a script, the through-line is the thread that ties the whole movie together. I used the same bamboo shades on every window in the house to emphasize my black, white, and fruitwood palette. You need a through-line in design, too!

It's a color scheme that lives happily with your mash-up of furniture periods and patinas.

A Victorian chair next to a modern chair — that's my style. I love those three chairs in the breakfast room and the mismatched chairs on the landing. They're all completely different, but they work together because they're similar in scale and the seats are the same height off the floor. As for patina, I believe every space needs something a little primitive. There's that beat-up coffee table in the living room, and the dining room table has kind of a driftwood feeling. It's like wearing jeans with Louis Vuitton heels — it relaxes things. This house is really all about me and my gigantic, 110-pound Swiss mountain dog, Theo, being comfortable.

Your version of comfort is pretty chic. I love the elegant black kitchen.

It's a 1920s kitchen, and it was hideous before, something right out of The Ghost and Mrs. Muir. It needed love! It needed glamour! But I didn't want to spend a lot of money. So I painted the cabinets glossy black, and I glazed the tile and sinks a crisp white. Then I hung a chandelier that I put together myself from a vintage brass fixture and a box of old crystals I bought at an antiques store. The whole thing cost less than $50. And it really does provide a lot of light over the sink. I'm not a huge fan of those pendant lights everyone is using in kitchens now. They've become so expected.

You seem to love wallpaper almost as much as you love mirrors.

The funny thing is that I used to hate wallpaper. I didn't do wallpaper for a solid decade and then suddenly decided I loved it and wanted it everywhere. I went crazy! I think these patterns in the bedrooms come right off the wall and give the rooms so much texture — they wrap you up and envelop you. The frames on all the upstairs mirrors are thicker than downstairs — they had to have more weight so they wouldn't be gobbled up by the strong wallpaper.

Wait! What happened to your 'neutrals only' diet in your bedroom?

I know — mustard! What can I say? I fell in love with this very French wallpaper pattern and I couldn't resist the classic palette of mustard with black and white. It's very traditional and appeals to the French château girl in me. I even have my Princess-and-the-Pea four-poster bed.

It's just dawned on me — any wall that doesn't have a window has a mirror.

That's right. No dead walls without some kind of reflection. I don't want there to be one place in the house where the energy stops. It just keeps going and going.